Where did it come from?

Thinking lately about printing presses and typewriters and political cults. The thoughts converged into the old phrase

Now is the time for all good men to come to the aid of the party.

I vaguely recalled using this for practice in high-school typing class. I didn’t like it. Unlike the quick brown fox, it doesn’t include all letters, and it’s propaganda.

Google yielded the origin: It was first written by Charles Weller in his history of the typewriter. I skimmed the book, hoping to find some new gadgets to animate, but it’s just a hagiography of Sholes.

Weller wrote:

We were then in the midst of an exciting political campaign, and it was then for the first time that the well known sentence was inaugurated, “Now is the time for all good men to come to the aid of the party;” also the opening sentence of the Declaration of Independence, “When in the course of human events,” etc., which sentences were repeated many times in order to test the speed of the machine.